As BLM, any where from 8 mins to 20 mins, depending on what time/day I am playing. But I would have to say 12-14 mins is about average for me as BLM. From what others have told me, this is normal queue time for DPS.

A few times I have queued with my tank that I am leveling, time is about 3-5 minutes, but it's all low level stuff too.